Inclosed or cartridge fuse



W. J. KRAMER.

INCLOSED 0R CARTRIDGE FUSE.

APPLICATION FILED JUNE 16. 1919.

Patented Aug. 23, 1921.

2 $HEETSSHEET l.

w. 1. KRAMER. INCLOSED 0R CARTRIDGE FUSE.

APPLICATION FILED JUNE lfil 1919- 1,388,269. I Patented Aug. 23; 192 1.

2 SHEETS-SHEET 2.

/5 I will! y @M/ZTTOR/YLY UNITED STATES, PATENT 0F WILLIAM ITOE KRAMER, OF LOUIS, MISSOURI..

To all whom it mayconcem:

Be it known that 1, WILLIAM J. KRAMER,

the city of St. Louis, State of Missouri, have invented a certain new and useful Improve ment in I'nclosed or Cartridge Fuses, of which the following is a specification, reference being had to the accompanying drawings, fo rming apart thereof.

This invention relates generally to elec-v trio safety fuses and, more particularly, to a certainnew and useful improvement in that class of electric safety fuses commonly known as renewable lnclosed or cartridge fuses.

The principal object of my present inven-' tion is to provide an inexpensive and efli-' cientffuse of the class and especially of the type mentioned comprising readily and conexpensive casing or shell and terminals or' other fittings of the fuse being retained and repeatedly used.

With the above and otherfobjects in view,

my present invention resides in the novel features of form,

pointed out in the claims. 7

In the accompanyingdrawing,

' Figure 1 is an elevational view, partly in longitudinal section, of a fuse constructed in accordance with and vention;

Fig. 2 is a similar viewof the fuse taken the. fuse;

Fig. 5 is a transverse sectional view of the Flg. 1; I Fig. 6 is a modified form of one of the end-closing members of the fuse for adapting the same to the ferrule-type; and

Figs. 7 and 8 are longitudinal and transverse sectional views, respectively, of afuse ofthe plug type, showing the'adaptation I p ification ofLetters Patent. 7 Ptttelltd Aug.

Application filed June 16,

holder 4 is substantially construction, arrange-f ment, and combination of parts hereinafter described and afterward embodying my in fuse taken approximately on the line 55,

perspective viewof a slightly shell 1, r

FICE.V,

INCLOSED OR CARTRIDGE FUSE.

23, 1921. 1919. Serial No. 3041481.

therefor of the fusible-strip or element I holder of the present fuse. a citizen of the United States, residing at Referring now more in detail to the said draw1ngs,.in which like reference characters refer to like. parts throughout the sev-. eral views, 1 indicates pacity of the fuse.

' Threadedto seat permanently upon the shell 1 at its opposite ends, are tubular p the fuse casing, which is preferably an open-ended tubular shell metallic ferrules 2+2, each provided inte- I riorly and intermediate its ends with an annularshoulder or flange 3 adapted at one or its inner face to abut against the end of the shell, as seen especially in Figs. 1 and 2, and at its other or outer face to form an abutment or seat for pearing. 4 indicates as a unit what I might designate the fusiblestrip holder. This a tubular casing longitudinally split into and comprising two separate, matching, and cooperating semi- -cylindrical, insulation members 55, each at its opposite ends provided with, and embedded in, a semi-cylindrical ferrule 6, the ferrules 6 having each an approximately. semi-cylindrical, solid tongue 7 within andproviding plug-terminals for the members 5, as seen especially in Fig. '3. Adapted to fit renewably wi thin the holder 4:, is a fusible element or strip 8, which may be of any suitable readily fusible metal or alloy, and'which is of the desired ampere carrying-capacity, as will be well understood. This strip 8 is of a length somewhat less than the length of, and to fit within,

members 5 ,of the holder the holder 4, the being adapted, in use, for longitudinal disposition upon the opposite flat faces of, and to correspondingly surround, the strip 8 and parts hereinafter ap disposed to engage electrically at the tongues 7 of their ferrules 6 with the strip.

The holder 4 is of reduced size, both in length and diameter, relatively to the shell 1, the holder 4 being adapted to fit longitudinally trated in Figs. 1 and 2; support and position the holder 4: within the provide sleeves 9-9 adapted to fit'within theshell and each having at its outer end an annular outstanding flange 1O adapted to seat or engage'at their inner face of and within the shell 1, as illus and to removably upon the outer face of the ferrules-flanges 3, as also seen especially in Figs. 1 and 2. The sleeves 9 are adapted to fit tightly, but removably, upon and engage the holder 4 at its ends, the sleeves 9 not only thus engaging electrically with the ferrules 6, but also firmly retaining the holder-members 5 oper-' atively around the strip and their ferrules 6 in electrical contact therewith. As the inclosed strip 8 may occasionally vary in thickness, the sleeves 9 are preferably provided longitudinally with a plurallty of kerfs, as at 11, wherebythe sleeves 9 are adapted to yield to accommodate in their engagement with the holder 2': strips 8 of varying thickness betweenthe holder-memfor convenient engagement by a spannerwrench or the like, not shown.

In the so-called knife-blade type of fuse, the disks 12 are integrally or otherwise suitably provided with knife-blade terminals 15 rigidly projecting outwardly'of the shell. In the so-called ferruletype of fuse, such terminals may be omitted and plain disks,

such ,as the disk 12 illustrated in Fig. 6,

substituted as and forthe disks 12. Thus. the fuse may be conveniently adapted for either type.

In assembling the parts of the fuse, the ferrules 2 are fixed upon the shell 1, as described. A strip 8 is then placed lengthwise.

between the holder-members 5, and a sleeve 9 fitted into engaging position upon the ferrules 6 thereof. The sleeve 9 and holder 4 are then inserted endwise into the shell from one end and the flange 10 of the sleeve 9 brought into engagement with the flange 3 of the ferrule 2 at such end of the shell. The other sleeve 9 is then inserted endwise into the opposite end of the shell and into 7 engaging position upon thecorresponding ferrules 6 of the holder: 41, andits flange 10 seated upon the ferrule-flange?) at such end of the shell. The disks 12 and rings 13 are then, respectively, seated within and en gaged with the ferrules 2, when the fuse is ready for use, the holder 41 being in electrical contact with the strip 8 and the sleeves 9 being in electrical contact with the holder 4 and with the disks 12 and ferrules 2, as

. before described. -On a blowing or disruption of the'strip 8 on an excess of current, 1t wlllbe 81 16161111 Without further explanation that, on removal of the retaining-rings 13, the other inclosed parts of the fuse may bereadily removed from the shell 1, a new strip 8 substituted within the holder 4, and the parts again assembled as described, the shell and all the other parts of the fuse being retained and repeatedly used.

l/Iy fuse embodies few, inexpensive, and readily manufactured parts, which may be quickly and conveniently assembled and dis assembled, as will be obvious from the foregoing description; the contacting-surface between the current carrying parts of the fuse is relatively large; and the parts are securely held together and from being blown off or from the shell on a disruption of the fusible-element or strip.

I am aware that changes in the form, construction, arrangement, and combination of the several parts of the fuse may be made and substituted for those herein shown and described without departing from the nature and principle of my invention. And as showing a modified adaptation or use of the holder of the fuse-strip, I have illustrated the same in Figs. 7 and 8 in connection with a fuse of the plugtype. In this type of fuse, the holder-members 55, surrounding and electrically engaging with the'strip, as before described, are held operatively together by, and are in electrical-engagement at their ferrules 6 with, spring-clips 1616' suitably mounted within the shell or body 17 of the fuse and, in turn,suitably electrically connected with the end and side terminals 18 and 19, respectively, of the fuse, the shell 17 being closed at its upper or open end by a suitable cap 20.

Having thus described my invention, what I claim and desire to secure by Letters Patent is:

1. In a renewable fuse, a tubular fusestrip holder including a pair of semi-cylindrical insulation members separate one from the other and adapted for cooperation to separably fit longitudinally upon the opposite fiat faces of and correspondingly surround a fuse-strip, and terminals fixed on the ends of said members for removably supporting, and engaging electrically with the ends of the strip.

2. In a renewable fuse, a tubular fusestrip holder including a pair of semi-cylindrical insulation members separate one from the other and adapted for cooperation to separably fit longitudinally upon the oppo site flat faces of and correspondingly surround a fuse-strip, and semicylindrical plug-terminals fixed on the ends of said members for removably supporting and en gaging electrically with the ends of the strip.

3. In a renewable fuse, a tubular fusestrip holder including a pair of semi-cylindrical insulation members separate one from the other, and ferrules fixed on said members and having semi-cylindrical tongues disposed within and plugging the ends of said members, said members being adapted for cooperation to separably fit longitudinally upon the opposite fiat faces of a fuse strip and to engage electrically therewith at said tongues. I

4. A renewable fuse including a tubular fuse-strip holder comprising a pair of semitachable engagement with the ferrules to separably maintain the holder-members and the strip in operative relation.

5. A renewable fuse comprising a shell and tubular ferrules fixed on the ends of the shell, in combination with a fuse-strip holder having current-conducting terminals fitting removably longitudinally within the shell, conducting retaining-members for the holder also fitting removably within the shell and engaging loosely with the ferrules and detachably with the holder, and closuremeans for the ends of the shell having detachable engagement with the ferrules.

6. A renewable fuse comprising a shell and tubular ferrules fixed on the ends of the shell, in combination with a fuse-strip holder having current-conducting terminals fitting removably longitudinally within the shell, conducting retaining-sleeves for the holder also fitting removably within the shell and engaging loosely with the ferrules and detachably with the terminals of the holder, and means having detachable engagement with the ferrules for locking the shell, sleeves, and holder operatively together.

7. A renewable fuse comprising a shell, a

fuse strip, and tubular ferrules fixed on the ends of the shell, in combination with a twopiece separable fuse-strip holder having current-conducting terminals fitting removably within the shell, conducting retainingsleeves also fitting removably within the shell and engaging loosely with the ferrules, said sleeves also embracing and engaging electrically with said terminals for separably maintaining the holder-parts and the fuse-strip in operative relation, and means including disks fitting removably in the ferrules for detachably locking the shell, sleeves, and holder operatively together.

8. A renewable fuse including, in combination, a shell, tubular ferrules fixed on the shell, a two-piece fuse-strip holder having current-conducting terminals disposed removably within the shell, a fuse-strip d1sposed renewably between, and engaging electrically with the terminals of, the members of theholder, and means including members engaging electrically with said terminals and disks fitting removably within the ferrules for operatively retaining the holder and surrounded strip operatively toget-her and within the shell.

9. A fuse comprising a shell and flanged ferrules on the ends of the shell, in combination with a two-piece fuse-strip holder adapted to fit longitudinally within the shell, flanged retaining sleeves for the holder adapted also to fit within the shell and to engage at their flanges with the flanges of the ferrules, said sleeves being adapted to embrace the holder for holding the parts thereof together and to engage electrically therewith, and end-members for the shell fitting within the ferrules and having engagement with the sleeves.

10. A fuse comprising a shell and flanged ferrules on the ends of the shell, in combination with a two-piece fuse-strip holder adapted to fit longitudinally within the shell, a fuse-strip disposed renewably within the holder and electrically engaging therewith, flanged retaining-sleeves for the holder adapted also to fit within the shell and to engage at their flanges with the flanges of the ferrules, said sleeves being adapted to embrace the holder for holding the parts thereof together and to engage electrically therewith, disks fitting within the ferrules and engaging the flanges of the sleeves, and see curing washers for the disks having engagement with the ferrules.

In testimony whereof, I have signed my name to this specification.

WILLIAM J OE KRAMER. 

